The present invention relates to passive function systems, such as passive entry systems, and specifically relates to a system that permits operation of a vehicle function, such as entry into a vehicle, when an authorized person is within a predefined range. Preferably, the authorized person is identified via communication that avoids communication interference and does not consume an undue amount of power.
Passive function systems are known. One particular example type of passive function systems is passive entry systems. Such systems permit automatic unlocking/opening of a secured entranceway for an authorized person wishing to gain entrance. Passive entry systems relieve the authorized person of the burden of manually turning a key in a lock, manually actuating a hand-held transmitter, manually inputting a code into a touch pad, or the like. One example type of such a passive entry system is for a vehicle that permits the authorized person to gain entrance through a vehicle door, or the like, into a secured portion of the vehicle such as an interior or a trunk area of the vehicle.
A passive system includes an identification transceiver carried on an authorized person and a base transceiver located in association with the secured entranceway. The base transceiver interrogates the identification transceiver, and in response to the interrogation, the identification transceiver outputs a signal that conveys an appropriate security code identification. In response to reception of the signal conveying the security code identification, the base transceiver outputs a function operation signal. Such systems are often referred to as radio frequency identification systems or contact-less identification and authentication systems.
In the case of a passive entry system, the output of the signal from the base received results in unlocking/opening of the secured entranceway. Thus, the authorized person may simply operate (e.g., lift/pull a door handle) the secured entranceway and/or pass through the secured entranceway.
Within a passive entry system, it is typically desirable to have the authorized person in close proximity to the secured entranceway when access through the secured entranceway is permitted. For example, for a passive vehicle entry system, the authorized person should be relatively near to the associated vehicle before a vehicle door is unlocked. Having the authorized person in close proximity to the vehicle upon unlocking of the vehicle door will help alleviate a possibility that an authorized person would be unaware that a vehicle door was passively unlocked.
For certain types of passive function systems, an interrogation sequence between a base transceiver and an identification transceiver results in power consumption at each transceiver. Often, identification transceivers are relatively small and have relatively small power supplies. For example, within passive vehicle entry systems, the power supply associated with the identification transceiver is a battery that is approximately the size of a small coin. The life of the battery is directly proportional to the amount of energy that the identification transceiver expends in outputting its response signal.
The person of ordinary skill in the art will appreciate that the communication exchange that occurs between a base transceiver and a portable transceiver must comply with regulations concerning frequency and maximum transmitted signal strength. In the United States, such regulations are imposed by the Federal Communications Commission (xe2x80x9cFCCxe2x80x9d) and are specifically directed to unlicensed transmission devices. In the United States, remote control communication for passive entry systems and the like typically occurs in the portion of the radio frequency (xe2x80x9cRExe2x80x9d) spectrum that is allocated by the FCC for unlicensed transmission devices. Typically, the communication exchange that occurs between a base transceiver and a portable transceiver is within the ultrahigh frequency (xe2x80x9cUHFxe2x80x9d) portion of the RF spectrum. However, the person of ordinary skill in the art will appreciate that noise can be present in certain parts of the RF spectrum.
Interference (e.g., radio frequency interference) caused by the noise may adversely effect some communication systems. The amount of interference may rise to the level of communication disruption. It is possible that some types of passive entry systems may be adversely effected by interference. The result would be that the authorized person would not have the convenience of passive performance of the function. For example, the authorized person would not have the convenience of passive entry (e.g., the authorized person would have to turn a key in a lock, manually input a code into a touch pad, or the like).
In accordance with one aspect, the present invention provides a system for remotely controlling a function. Means outputs a function request signal at one of a plurality of frequencies. Means receives the function request signal and performs the requested function in response to receipt of the function request signal. Means, associated with the means for receiving the function request signal and for performing the requested function, selects the one frequency at which the means for outputting outputs the function request signal and provides the selected one frequency to the means for outputting.
In accordance with another aspect, the present invention provides a system for remotely controlling access through a securable entrance. Means outputs an access request signal at one of a plurality of frequencies. Means receives the access request signal and permits access through the entrance in response to receipt of the access request signal. Means, associated with the means for receiving the access request signal and for permitting access, selects the one frequency at which the means for outputting outputs the access request signal and provides the selected one frequency to the means for outputting.
In accordance with another aspect, the present invention provides a system for remotely controlling a function. Means outputs function request signals, each function request signal being at a different frequency. Means receives the function request signals. Means performs the requested function in response to receipt of at least one function request signal by the means for receiving. Means causes the means for outputting to continue to output the different frequency function request signals until the means for receiving receives the at least one function request signal.
In accordance with another aspect, the present invention provides a system for remotely controlling access through a securable entrance. Means outputs access request signals, each access request signal being at a different frequency. Means receives the access request signals. Means permits access through the entrance in response to receipt of at least one access request signal by the means for receiving. Means causes the means for outputting to continue to output the different frequency access request signals until the means for receiving receives the at least one access request signal.
In accordance with another aspect, the present invention provides a system for remotely controlling access through a securable entrance. Control means permits access through the entrance in response to receipt of an access request command. Base transceiver means, associated with the control means, outputs and receives signals that comprise communication to achieve receipt of the access request command at the control means. Portable transceiver means outputs and receives signals of the communication that includes outputting a signal that conveys the access request command. At least one of the base transceiver means and the portable transceiver means includes means for changing frequency of signals output therefrom.
In accordance with yet another aspect, the present invention provides a system for remotely controlling access through a securable entrance. Control means permits access through the entrance in response to receipt of an access request command. Base transceiver means, associated with the control means outputs and receives signals that comprise communication to achieve receipt of the access request command at the control means. Portable transceiver means outputs and receives signals of the communication that includes outputting a signal that conveys the access request command. One of the base transceiver means and the portable transceiver means includes means for outputting signals via provision of magnetic fields. The other of the base transceiver means and the portable transceiver means includes means for outputting signals via radio frequency broadcasts.
In accordance with yet another aspect, the present invention provides a method for gaining access through a securable entrance. A frequency at which an access request signal is to be output from a requesting location is selected at a receiving location. The selected frequency is provided to the requesting location from the receiving location. The access request signal is output at the selected frequency from the requesting location. The access request signal is received at the receiving location. Access is permitted through the entrance in response to receipt of the access request signal.
In accordance with still another aspect, the present invention provides a method for gaining access through a securable entrance. Access request signals are output. Each access request signal is at a different frequency. At least one of the access request signals is received. Access through the entrance is permitted in response to the receipt of the one access request signal. The step of outputting access request signals at different frequencies continues until the one access request signal is received.
In accordance with still another aspect, the present invention provides a method for gaining access through a securable entrance. An interrogation signal is output to a requesting location from a door access control location. The interrogation signal is received at the requesting location. An access request signal is output to the door access control location from the requesting location. The access request signal is received at the receiving location. Access is permitted through the entrance in response to receipt of the access request signal. One of the interrogation signal and the access request signal is conveyed via a magnetic field and the other of the interrogation signal and the access request signal is conveyed via radio frequency broadcast.